It is known to use a single torsional vibration damper or a series torsional vibration damper in a torque converter. The preceding configuration provides a torque path from a cover of the torque converter to an output of the torque converter through the damper configuration. In general, dampers are tuned according to the expected torque loads on the dampers. For example, the spring rates for the springs in a damper are selected according to the expected torque load. For lower torque loads, for example associated with two-cylinder mode, the spring rates must be relatively low and for greater torque loads, for example, for a four cylinder engine, the spring rates must be relatively higher. However, the preceding requirements create a conflict when the expected torque load on the damper includes too broad a range. For example, a four cylinder engine with a two cylinder mode requires the relatively higher spring rates noted above for operation in four-cylinder mode. However, the higher spring rates render the damper ineffectual for the two-cylinder mode. That is, due to the higher spring rates, the damper is too stiff in the two-cylinder mode and an undesirable amount of vibration passes through the damper.
U.S. Pat. No. 7,044,279 teaches the use of two clutches in a torque converter. However, U.S. Pat. No. 7,044,279 teaches a single damper. Therefore, regardless of the clutch closed, all vibration attenuation is linked to the spring rates of the single damper.